Railroad draft gear friction shock absorbing mechanism



G. E. DATH Aug. 26,l 1947.

RAILROAD DRAFT GEAR FRICTION SHOCK ABSORBING MECHANISM Filed Aug. 25, 1944 Patented dging. 26, i947 RAILaoAn DRAFT GEAR {Farc'rioN s'HooK Aesolnnlno MnoHANlsr/i George E. Dath, Mokena, 111.,.assignor to W. H. Miner, Inc., Chicago, Ill., a corporation of Delaware Application August 25, 1944, -SerialNoSlLZ l Claims. (Cl. 213-24) This invention relates to improvements in lfriction shock 'absorbing mechanism, especially adapted for railway draft riggings.

One object `of the invention is to vprovide a friction shock absorbing mechanism comprising a friction casing open at the front-l and rear ends, havin-g a ,friction shell section vat the front end thereof; a friction clutch within the -friction shell section of the casing, including a, wedge and friction shoes, the wedge having shouldered engagement with theecasing at the'friction shell end thereof to limit outward movement of the Wedge, the wedge being insertable through the open rear end of ythe casing in assembling the mechanism; a spring resistance Within the casing yieldingly opposing inward movement of the clutch; and a two-piece Vspring cap closing the rear `end of the casing, wherein the spring cap has restrictedmovement with respect to the casing to provide for preliminary spring actionof the mechanism.

A more speciiic object of `t-he invention Vis to provide in the mechanism as `set forth in the preceding paragraph, a two-piece, sectional spring cap, the sections of which are separately engageable with the casing by relative rotary displacement of thesame and the casing, and are retained in assembled relation with the casing by guide means on the casing vholding `one .of said sections against rotation with respect to the casing and means on said last .named `section interlocked with the other.sectionforpreventing rotation of said .other section with `respect to .the

casing.

Other objects `of .the invention will vmore .clearly appear from the descriptionand claims hereinafter following.

VInthe drawing forming a part. of .this specifica` D comprising two nestedlcuplike members; and a spring-resistance The casing A is inthe form of a tubular `member openat its .front and rear ends. The front end portion IU of the casing is of hexagonal, transverse cross section, as will be clearly seen from Figure 1. rThe rearend'portion of the castion, Figure lis a front elevational View of .a friction shock `absorbing mechanism, embodying `my invention. Figure 2 isa horizontal, .longitudinal sectional view, corresponding.substantiallyto the line 2-2 of Figure l. Figures'and 4 are transverse, vertical sectional views, 1corresponding respectively to the lines "3--3 and 4-4 ofFigure 2. Figure 5 is a horizontal, `longitudinal sectional View, similar to"Figure 2, of the'rear end portion only of the casingof the mechanism, all other parts being omitted'insaid View. Figure 6 is a side elevational view `ofthe `.two-piece spring cap of theimprovedmeehanism.

-As shown in the drawings, my limproved `friction vshock absorbingmechanism comprisesibroad- 1y a friction casingn; a wedge IblockB; 'three friction :shoes -CCC a two-piece spring cap ing-is enlarged, as indicated at H, said enlarged portion comprising apair` of side members l'2--l,2, and a frustoeconical section I3 connecting .the side members i2 tothe hexagonal portion of the casing. At the forward end Iof the casingfthe walls thereof are thickened, as indicated at .Il. This thickened :portion ofthe casing forms the friction shell proper ofthe mechanism. The friction shell section Aof `the casing is provided with three longitudinally extending, interior friction surfaces 'i5-1.5mm of Vshaped,.transverse cross section. Thefriction surfaces IE-lE-i are-preferably converged inwardly of the mechanism, `thereby -providing a tapered friction shell. At the outer end ofthe friction shell section, that is, forwardly of the friction surfaces IE-l-l, the casing :is provided with an inturned retaining ange I .which is continuous around thecasing. The ,sidemembers J2, at the rear end of the casing, each comprise a vertically extending, curved Wall H `which `continues rearwardly from the frusto-conical portion i3 ofthe casing. At the rear end thereof, each `wall ll `has a vertically extending, laterally .inturned flange i3 which forms a rear stop `on .the casing. rihe flanges Iii-|18 of the walls ll-Il of the side members I2--I2 :are `in Vtransverse alignment. *Interiorly of the-leasing, at `the enlarged portionthereof, are provided transversely disposed, laterally spaced, vertical webs, or ribs, `l,9l`9, which `are located at the front ends of the wal-ls il -of the side membersl l2 4where the same join the `frusto-conical portion I3. The spaced arrangement of the webs ifsi9 provides an opening therebetween, which is adapted to accommodate the spring resistance E. The wall vllof each side memberlZ ,is-further provided with longitudinally extending, interior, top and bottom rflanges or 4ribs ZEB-ZiLewhichare f ormed `by thickening said `walls atthe 4top and bottom `end edgesthereof. The ribs `Eil-W26 present horizontal .longitudinally extending faces El-eZl, which 4together withthe innersides of the walls ifi-L1 .form guideways extending length'- wise of themechanism. The flangesZ-.Z'terminato shortoffthe rear endsof the'walls H--il thus Iproviding openings '22--122 between `,the flange 1.8 `and the rear endslof thelfianges .2Q-Eil to permit assembling of the cuplike members of the spring cap D with the casing A.

The spring cap D comprises nested inner and outer cuplike members 23 and 2li. The member 23 is in the form of a cylindrical, tubular sleeve, closed at the outer end by a transverse vertical wall 25. At the front end, the cup 23 is provided with laterally outwardly projecting, relatively thick flanges 2-2(, which are at diametrically opposite sides of the cup. The flanges 26 are of a height to llt between the top and bottom flanges 2-2 of the walls l-ll and have their outer end edges curved concentric to the inner surfaces of the walls Ii-I'l to llt the same. The flanges 26-26 are thus guided in the guideways of the walls I'i-ll to hold the cup 23 against rotation. It is further pointed out that the flanges 26-26 are of such a thickness that they will pass freely edgewise through the openings 22-22 between the rear ends of the flanges 22-26 and the inturned rear flanges l 8 2 8 of said walls.

The member 2li of the cap D is also in the form of a cylindrical sleeve having top and bottom, lengthwise extending openings Zl-Z'i. Vertically extending side walls 28-28 are thus provided at opposite sides of the mechanism. The side walls 2&-28 extend lengthwise of the device and are curved in vertical direction, being concentric. The opposite end edges of the walls S28-28 are spaced apart at the top and bottom of the member 2d, thereby providing the openings 27 21 hereinbefore referred to. The side walls 253-28 are connected by a transverse, outer, vertical end wall 29, which is extended laterally outwardly beyond the side walls to provide flanges 321-38 at opposite sides of the cup member. The wall 2S has a central opening 3l provided for a purpose hereinafter pointed out. At the forward end, the cup member 24 has a pair of laterally outwardly projecting flanges 32-32, which llt the guideways of the walls Ill-ll of the side members |2-l2 of the casing, and are similar to the flanges 26-25 of the member 23, being of an overall thickness to pass in edgewise direction freely through the openings 22-22 between the rear ends of the flanges 29-29 and the flange l 8 of the side member. The cup-shaped member 24 is of larger diameter than the member 23 to accommodate the latter nested therein with the flanges 25--26 thereof bearing on the front faces of the flanges 32-32 of the cup 2d. The member 24 has the ilanges 32-32 thereof provided with forwardly extending, radial ribs 333, which are at diametrically opposite sides of said member and are engaged in seats 34-34 in the flanges 26-26 of the member 23. The seats 3&-34 are in the form of radially disposed slots, which are at diametrically opposite sides of the member 23. The ribs 33-33, when seated in the slots 34-34, lock the two cup-shaped members of the cap D together against relative rotation. As shown most clearly in Figure 6, the ribs 33-33 preferably have their opposite side edges beveled olf and the side walls of the slots 31%-34 are correspondingly beveled to fit the beveled portions of the ribs.

The wedge B is in the formof a hollow block having three inwardly converging wedge faces 35-3 5 35 arranged symmetrically about the central longitudinal axis of themechanism. The outer end of the block B extends beyond the front end of the casing and engages the usual main follower of the railway draft rigging. At the outer ends of the wedge faces 35-35-35 of the wedge block B, an annular stop shoulder 36 is provided, which engages in back of the inturned flange l of the casing to limit outward movement of the block.

The friction shoes C, which are three in number, are arranged about the wedge block B and have V-shaped, outer friction surfaces 3'l-3'l-3'!, which cooperate with the friction surfaces 5- IS--IE of the casing A. On the inner side, each friction shoe is provided with a flat wedge face 38 correspondingly inclined to and engaging one of the wedge faces 35 of the wedge block,

The spring E, which comprises a relatively heavy outer coil and a lighter inner coil is disposed within the casing A and has its front and rear ends bearing respectively on the inner ends of the shoes C-C-C and the transverse wall 25 of the cup member 23 of the two-piece spring cap D.

In assembling the parts of my improved mechanism, the wedge block B, shoes C-C-C, and the spring E are inserted within the casing through the open rear end thereof and the wedge block B is brought into shouldered engagement with the flange i6 at the front end of the casing. The cup member 23 of the cap D is then applied by engaging the flanges 26-26 thereof through the openings 22-22 of the side members l2-i 2, by rotation of said cup member. The cup member 2li is next applied, the spring resistance E being compressed by a suitable tool, such as an elongated bar, which is engaged through the opening 3l of the member 25 and pressed against the cup 23. The spring E is compressed to a sufcient extent to dispose the flanges 26-26 of the cup member 23 forwardly beyond the openings 22-22 of the side members l2-l2. The flanges 32-32 of the cup member 24 are then engaged within the guideways of the side members 2-l2 by passing the same through the openings 22-22 in edgewise direction, the cup 2li being rotated. After the cup 24 of the cap D has been turned to a position to align the flanges 32-3Z thereof with the guideways of the members |2-I 2, the pressure is removed from the cup 23, thereby permitting the mechanism to expand and forcing the cups 23 and 2li to the normal position shown in Figure 2, with the flanges 32-32 of the cup 24 shouldered against the flanges l8-l8 of the side members l2-l2 and the ribs 33-33 of the cup member 23 seated in the slots 311-313 of the cup member 23. As will be evident, the travel rearwardly of the cup member 23 is limited by engagement thereof with the ilange of the cup member 2d so that the flanges 26-26 cannot pass beyond the inner end Walls of the openings 22-22 of the members l2-l2, thus maintaining the flanges 25-25 in operating engagement with the ribs or flanges 20-20 and 20-2!) of the members i2-l2 and positively preventing rotation of the cup member 23. Inasmuch as the cup member 24 is interlocked against rotation with respect to the cup member 23 by the interengaging ribs 33-33 and slots 311-34 of the cup members, rotation of the cup 24 with respect to the casing is prevented, thereby maintaining the flanges 32-32 thereof in longitudinal alignment with the stop flanges Iii-I8 of the side members |2-I 2 of the casing,

The operation of my improved shock absorbing mechanism is as follows: Upon theV mechanism being compressed between the front and rear followers of the draft rigging, the pressure exerted on the wedge B Wedges the shoes against the friction surfaces of the casing, thereby clutching the casing and causing the same to move lengthwise with the shoes and toward the spring cap D. The spring resistance E is thus compressedduring the initial action of the mechanism, thereby providing preliminary spring action. The preliminary spring action of the mechanism continues until relative movement of the cap D and the casing A is limited by engagement ofthe flanges 25-26 of the cup member 23 with the Webs or ribs IS-il of the casing A and the follower flanges :B9-3o of the cup Z4 with theinnerend of said casing. Upon relativemovement of :the spring'cap D and the casing A being arrestedthe friction shoes are forced to move inwardlyofthe casing during the remainderof the compression stroke of the mechanism, .therebyproviding high frictional resistance during the last part of the compression stroke.

I have'herein shown and described whatl now consider` the preferred manner of carrying out my invention, but theisame is "merely illustra-tive and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

1. In a friction shock absorbing mechanism, the combination with a casing having a friction shell section at one end; of a two-piece spring cap slidingly telescope'd within the other end of the casing, said spring cap comprising a pair of nested cup-shaped members, each cup-shaped member having guide anges thereon, the flanges of each member of said pair overlying the corresponding flanges of the other member in registering relation; interengaging means on said overlying flanges of said members locking the same against relative rotation; longitudinally extending guideways in said casing slidingly receiving the guide flanges of said members and holding said members against rotation with respect to the casing, said guideways-being providedwith lateral openings through which the guide flanges of said members may pass freely in edgewise direction; a friction clutch slidingly telescoped within the friction casing; and spring means within the casing extending lengthwise thereof and bearingat opposite ends on said clutch and spring cap respectively to yieldingly oppose movement of said clutch and cap inwardly of the casing,

2. In a friction shock absorbing mechanism, the combination with a casing having a friction shell section at one end; of a two-piece spring cap slidingly telescoped within the other end of the casing, said cap comprising a pair of nested cupshaped members, each cup-shaped member of said pair having guide flanges thereon, the flanges of each member of said pair registering with the respective flanges of the other member of said pair; interengaging means on said registering flanges of said members for locking Said members against relative rotation; a stop shoulder on the casing at said second named end thereof with which the flanges of one of said cup-shaped mem-1 bers is engageable to limit outward movement of said member; spaced, longitudinally extending, interior guideways on said casing at said second named end thereof, each guideway being defined by a pair of longitudinally extending spaced ribs between which one set of registering flanges of said two members of said pair is guided, said ribs terminating short of said stop shoulder, the flanges of each of said members being of a Vthickness to pass freely edgewise between the ribs and stop shoulder of the casing; a friction clutch slidi ingly telescoped Within the friction shell section of the casing and spring means within the casing extending lengthwise thereof and .bearing at op posite ,ends on saidclutch and spring cap respectively and yieldingly Opposing movement ,of said clutch and cap inwardly `of the casing.

3. In a friction shock absorbing mechanism, the combination with` a casing having a friction shell section at .one end and longitudinally extending, laterally spaced, `opposed guide walls at the other end; of longitudinally extending, top and bottom, interior guide ribs on each of said walls; an inturned, vertical stop flange at the outer end of each wall, spaced from the lends of the guide `flanges of `said wall; a two-piece spring cap comprising a pair of nested cup-shapedmembers, each cup-shaped member having laterally projecting guide anges at opposite sidesthereof,

each of said guide flanges being lembraced by .and guided between the corresponding top `and bottom ribs of said walls, the flanges of one of said members being engageable with said stop flange to limit outward movement of the cap, and the flange of the other member being embraced ,by said top and bottom guide ribs in all operative positions of said capsaid flanges of each of said cup-shaped members being of a size to pass edgewise freely through the space between the ends of the guide ribs and the stop flange; a locking projection on the flanges of one of said cup members engaged in seats on the flanges of the other cup member to lock said members against relative rotation; a friction clutch slidingly telescoped within the friction casing; and a spring within the casing yieldingly opposing inward movement ofsaid clutch and spring cap respectively.

`Il. `in a friction shock absorbing mechanism,

`the combination with` a casing having afriction shell section at one end provided with aninturned `stopflange at itsouterend; of a two-piece spring cap `.slidingly telescoped within the other .end of the casing, said cap comprising a pair of nested cup-shaped members; interengaging `means on said cup-shaped members for ,locking saine against relative rotation; cooperating `guide means on said cup members and casingfor guiding thecup members lengthwise of the casing and holding the same against rotation with respect to the casing, comprising a longitudinally extending guideway on said casing and a flange on each cup-shaped member engaged in said guideway; a friction clutch slidingly telescoped within the friction shell section of the casing, said clutch including a wedge block having a shoulderen gaging said stop flange on its inner side; and spring means within the casing yieldingly opposing movement of said clutch and spring cap inwardly of the casing toward each other.

5. In a friction shock absorbing mechanism, the combination with a casing having a friction shell section at one end provided with an inturned stop flange at its outer end; of a two-piece spring cap slidingly telescoped within the other end of the casing, said spring cap comprising a pair of nested cup-shaped members, each `cup-shaped member having laterally projecting guide flanges thereon, the flanges of one of said members registering respectively with the flanges of the other member to provide registering pairs of flanges;

interengaging means on said flanges of each pair of locking said members against relative rotation; longitudinally extending guideways in said casing, each guideway slidingly receiving one of said registering pairs of guide flanges of said members and holding said members against rotation with respect to the casing; each of said guideways being provided with lateral openings through which the individual guide flanges of said members may pass freely in edgewise direction; a friction clutch slidingly telescoped within the friction casing, said clutch including a wedge block adapted to shoulder against the stop flange; and spring means within the casing extending lengthwise thereof and bearing at opposite ends on said clutch and spring cap respectively to yieldingly oppose movement of said clutch and cap inwardly -of the casing.

6. In a friction shock absorbing mechanism,

vthe combination with a casing having a friction shell section at one end provided with an inturned vstop flange at its outer end; of a two-piece spring cap slidingly telescoped within the other end of the casing, said cap comprising an outer cupshaped member and an inner cup-shaped member in nested arrangement, each cup-shaped member having a guide flange thereon, said guide flanges of said members being in superimposed registration; interengaging means on said flanges of said members for locking said members against relative rotation; a stop shoulder on the casing at said second named end thereof with which the flange of one of said cup-shaped members is engageable to limit outward movement of said member; spaced, longitudinally extendingy interior guide ribs on said casing at said second named end thereof between which the registering flanges of said members are guided, said ribs embracing the flange of Said inner cup-shaped member in all operative positions thereof, said ribs terminating short of said stop shoulder, the flange of each of said members being of a thickness` to pass freely edgewise between the ribs and stop shoulder of the casing; a friction clutch slidingly telescoped within the friction shell section of the casing, said clutch including a Wedge adapted to shoulder against the stop flange; and spring means within the casing extending lengthwise thereof and bearing at opposite ends on said clutch and spring cap respectively and yieldingly opposing movement of said clutch and cap inwardly of the casing.

7. In a friction shock absorbing mechanism,

8 the combination with a casing having a friction shell section at one end provided with an inturned stop flange and longitudinally extending, laterally spaced, opposed guide walls at the other end; of longitudinally extending, top and bottom, interior guide ribs on each of said walls; an inturned, verticalstop flange at the outer end of each wall, spaced from the outer end of one of said guide ribs of each of said walls; a two-piece spring cap comprising a pair of nested cup-shaped members, each cup-shaped member having laterally projectng guide flanges at opposite sides thereof respectively registering with the flanges of the other member and guided between the top and bottom ribs of said walls, the flanges of one cf said members being engageable with said stop flange to limit outward movement of the cap, and the flanges of the other member being embraced between said ribs in all operative positions of said cap, said flanges of each of said cup-shaped members being of a size to pass edgewise freely through the space provided between the ends 'of the guide ribs and the stop ange; a locking projection on the flanges of one of said cup members engaged in seats on the flanges of the other cup member to lock said members against relative rotation; a friction clutch slidingly telescoped within the friction casing, said clutch including a wedge adapted to shoulder against the stop flange of the friction shell section; and a spring within the casing yieldingly opposing inward movement of said clutch and spring cap respectively.

GEORGE E. DATH.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Certificate of Correction Patent No. 2,426,262. August 26, 1947. GEORGE E. DATH It is hereby certied that error appears in the printed specieation of the above numbered patent requiring correction as follows: Column 6, line 71, claim 5, before locking strike out of; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 25th day of November, A. D. 1947.

THOMAS F. MURPHY,

Assistant Uommz'ssz'ouar of Patents. 

